This invention is in the field of truck mounted hoists or gin poles.
It has heretofore been proposed to mount gin poles or hoists devices on truck beds, but such devices have not been entirely satisfactory. In most instances (see U.S. Pat. No. 2,181,253), the hoist mechanism when stowed on the truck bed for transport interferes with use of the truck bed for any other purpose. Furthermore, as shown in the patent, the length of the gin pole is somewhat limited.
It has also been proposed to increase the length of the gin pole by having the same articulated so that it can be folded for stowage on the truck or tractor. See, for example, U.S. Pat. Nos. 2,682,957, 3,092,367 and 3,158,266. In these instances, however, the foldable gin pole structure is of complicated shape and complicated mechanisms are provided for extending the same. They also contemplate use of such foldable gin poles only on tractor devices, having no other utility than use as a hoist or as a tractor for a trailer.